It is conventionally known that some amplification-type solid-state imaging elements, as represented by complementary metal-oxide semiconductor (CMOS) image sensors, use a method of reading out capacity load, as is disclosed for example in Japanese Unexamined Patent Application, Publication No. Hei 7-283386 (hereinafter referred to as “JP Hei 7-283386”). The amplification-type solid-state imaging element converts signal charges accumulated in the photodiode to a signal voltage in each pixel and outputs the voltage to each signal line. According to JP Hei 7-283386, a signal voltage output from each pixel is temporarily held in a load capacity element connected to each signal line and then read out to a horizontal signal line. In such a read-out operation, there is no need to feed constant current to each pixel from a constant current source connected to the signal line, thus allowing reduced power consumption.